The roof of the stadium hosting the World Cup opener in a few weeks will not be fully finished in time for the tournament, constructors said on Friday.

Construction company Odebrecht confirmed that a part of the roof at the Itaquerao will only be completed after the World Cup.

There was not enough time to install the glass covers that were supposed to be added to the sides of the stadium's roofing structure, so Odebrecht and local organisers have decided to postpone the work until after the tournament.

Shambles! The Itaquerao in Sao Paulo won't be completed before the World Cup starts (picture taken in March)

Odebrecht said the missing covers will not affect fans watching matches in the stadium.

The company in charge of 20,000 temporary seats needed for the opener said it has successfully addressed all health and safety issues that had prompted prosecutors to threaten to halt work at the venue.

Odebrecht said in an email that the glass covers will only be installed after the World Cup because 'transparency studies' were still being finalised to make sure the covers can allow the passage of the proper amount of light needed to 'preserve the pitch in good conditions'.

The company said the roof itself is ready and guaranteed that the covers are not essential, even though they were part of the initial project.

Some reports said the glass covers were needed to help protect fans from rain, but Odebrecht denied that their absence would keep fans uncovered. The company had already said that not all fans seated behind the goals will be fully covered from rain during the World Cup.

Sure? The construction company said no fans will be left uncovered at the ground (picture taken on May 8)

Major blow: The stadium's roof will now only be completed after the World Cup has ended (picture taken May 8)

FIFA and the local World Cup organising committee did not respond to requests for comment. The Itaquerao is one of the three stadiums yet to be completed ahead of the World Cup. Late last year, two workers died after a crane collapsed while hoisting a huge roofing structure, causing significant construction delays at the venue that was expected to be ready by the end of last year.

In March, another worker died while installing the temporary seats there, prompting labor officials to halt construction and causing another delay.

On Thursday, prosecutors said they found health and safety irregularities at the Itaquerao and threatened to stop the installation of the temporary seats that are still missing. The company in charge of the work, Fast Engenharia, said on Friday that it addressed all the problems pointed by prosecutors and dismissed the possibility of another work stoppage.

In his latest visit to Brazil last month, FIFA Secretary General Jerome Valcke said there was 'not a minute' to waste if local organisers wanted to make sure the Itaquerao was ready for the opener.